• 품질경영학회지
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• 제17권1호
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• pp.1-10
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• 1989

In general, the characteristics of components which consist of multi-component system can not be the same. This paper proposes a maintenance model of multi-component system considering the characteristics of each component. In this paper, multi-component system is divided into three components-critical unit, major unit and minor unit, respectively. This paper determines the optimal replacement time of the system which minimizes total maintenance cost, optimal replacement period of major unit and initial stock quantity of minor unit within this optimal replacement time. Numerical examples are shown when the failure times of each unit have gamma distribution.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.556-559
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• 2006

We successfully developed a high performance and highly reliable blazed GxL device with a high optical efficiency and a high contrast ratio. The device demonstrated superior resistance against a high power laser, which is suitable for a large-area laser projector. We operated the world's largest laser projection screen using this device at the 2005 World Exposition in Aichi, Japan, problem free.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2000년도 추계학술대회
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• pp.387-395
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• 2000

Circular consecutive-k-out-of-n:F system when the failure of component is dependent is studied. We assume that the failure of a component in the system increase the failure rate of the survivor which is working just before the failed component. In this case, a mean time to failure (MTTF), a average failure number of the system, and the expected cost per unit time are obtained. Then the minimum number of consecutive failed components to cause system failure to minimize the expected cost per unit time is determined as searching paths to system failure. And various numerical examples are studied.

• Communications for Statistical Applications and Methods
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• 제14권3호
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• pp.577-582
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• 2007

A continuum structure function (CSF) is a non-decreasing mapping from the unit hypercube to the unit interval. A B-type CSF, defined in the text, is a CSF whose behaviour is modeled by its underlying binary structures. As the measure of importance of a system component for a B-type CSF, the structural and reliability importance of a component at a system level ${\alpha}$(0 < ${\alpha}$ < 1) are defined and their properties are deduced.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.604-605
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• 2008

Modal participation factor (MPF) is a widely used in a mode-coupling squeal noise problem for finding the most sensitive component over a complex brake system in a vehicle using eigenvectors of sub-components. This methodology requires the problematic total response of system by the unstable squeal noise at a specific frequency as well as eigenvectors of each component belonging to brake system. In this paper, a unit-force response analysis is performed for intact total system to obtain eigenvectors of each component and then such data is directly used for the contribution analysis of a squeal noise problem. Since the eigenvectors of each component induced from virtual unit-excitation is most reliable owing to the intact boundary condition, it can be expected that the corresponding contribution analysis with MPF also provides a trustworthy result.

• 한국컴퓨터정보학회논문지
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• 제11권6호
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• pp.27-33
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• 2006

본 논문에서는 컴포넌트 설계와 이를 기반으로 한 검색 프로토타입을 제시하였다. 재사용 단위로 단일 객체만을 대상으로 하게 되면 연관관계가 있는 객체간 상호작용을 이해하기 어렵고 관련성 유지가 어렵다. 따라서 본 논문에서는 재사용 단위로 클러스터링 컴포넌트 제안하였다. 이것은 객체간 관련성과 연관관계를 부여하여 사용자가 컴포넌트를 이해하고 검색할 수 있도록 하였다. 제안한 프로토타입 시스템은 애매한 검색 정의에 대하여 3가지 검색 환경을 제시하여 정확한 검색을 가능하게 하였다.

• 한국정밀공학회지
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• 제20권7호
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• pp.233-240
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• 2003

Recently, the world are preparing for new revolution, called as If (Information Technology), NT (Nano-Technology), and BT (Bio-Technology). NT can be applied to various fields such as semiconductor-micro technology. Ultra precision processing is required for NT in the field of mechanical engineering. Recently, together with radical advancement of electronic and photonics industry, necessity of ultra precision processing is on the increase for the manufacture of various kernel parts. Therefore, in this paper, stability of ultra precision cutting unit is investigated, this unit is the kernel unit in ultra precision processing machine. According to alteration of shape and material about hinge, stability investigation is performed. In this paper, hinge shapes of micro stage in UPCU(Ultra Precision Cutting Unit) are designed as two types, where, hinge shapes are composed of round and rectangularity. Elasticity and strength are analyzed about micro stage, according to hinge shapes, by FE analysis. Micro stage in ultra precision processing machine has to keep hinge shape under cutting condition with 3-component force (cutting component, axial component, radial component) and to reduce modification against cutting force. Then we investigated its elasticity and its strength against these conditions. Material of micro stage is generally used to duralumin with small thermal deformation. But, stability of micro stage is investigated, according to elasticity and strength due to various materials, by FE analysis. Where, Used materials are composed of aluminum of low strength and cooper of medium strength and spring steel of high strength. Through this stability investigation, trial and error is reduced in design and manufacture, at the same time, we are accumulated foundation data for unit control.

• 한국주거학회논문집
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• 제17권3호
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• pp.41-49
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• 2006

Precast concrete apartments were main stream of domestic industrialized housing around 90's, and Steel Houses applying Steel Stud technique with light weighted steel have been dominant portion since 1995. On the other hand, various building techniques including Steel Stud method and highly prefabricated and industrialized Unit method are prevailing in developed countries like Japan. Steel stud and unit box have their own merits and demerits, but the more crucial aspect is that the constant design standard should be applied in each design procedure. It entails the necessity of industrial housing development on the open system basis. In this study, the design standard for unit house will be established coping with the established preparing standard for design specifications defined by architectural law and promotion law of housing construction. That is for design standard of industrialized private housing on the open system basis. This study attempts to propose the design automation, with the method of unit construction of which the rate of pre-fabrication is the biggest, that can cope with the demand of user on the basis of open-system. Ticky-tacky is the biggest technical problem in suppling industrialization housing. Therefore, we will suggest a basic plan for design automation of unit modular housing which can raise the productivity of industrialization housing by applying open system, utilized by DB of component and unit, and solve the problem concerned about ticky-tacky.

• 한국건축시공학회지
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• 제7권4호
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• pp.139-144
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• 2007

The purpose of this study is to analyze concrete characteristics by admixing agent and additive contents according to the change of unit-water to identify its effect on compressive strength. First of all, as for flesh concrete, overall unit-water showed a tendency to decrease as component inclusion rate of admixing agent was increased. In addition, air content showed a tendency to increase by increasing WR, WB, NP series admixing agent contents, on the other hand, the change of air content was gentle by around $1.5{\pm}0.5%$ for S, T, M series agents. Bulk density showed an inverse proportion to the change of air content. As for hardened concrete, expression rate of 3-day age compressive strength was generally decreased for S, T, WR, WB, NP, M series admixing agent component. Also, expression rate of 7-day age compressive strength showed an excellent record for S, M series agents, and expression rate of 28-day age compressive strength showed a tendency to increase more than plain on the whole.

• Korean Journal of Mathematics
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• 제5권1호
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• pp.55-60
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• 1997

A continuum structure function(CSF) is a non-decreasing mapping from the unit hypercube to the unit interval. The reliability importance of component $i$ in a CSF at system level ${\alpha}$, $R_i({\alpha})$) say, is zero if and only if component $i$ is almost irrelevant to the system at level ${\alpha}$. A condition to check whether a component is almost irrelevant to the system is presented. It is shown that $R^{(m)}_i({\alpha}){\rightarrow}R_i({\alpha})$ uniformly as $m{\rightarrow}{\infty}$ where each $R^{(m)}_i({\alpha})$ is readily calculated.